In broadest terms, the objective of the research project is to investigate the metabolism of biologically significant molecules in vertebrate retinal cells at the cellular and subcellular level. By means of electron microscope autoradiography and radiobiochemical techniques, we propose to investigate the intracellular sites of uptake and the subsequent fate of selected precursor molecules of known importance. Emphasis will be given to the functional behavior of individual organelles in the visual cells and pigmented epithelium of the retina. By extension, we hope to develop insights into repair mechanisms in visual cells as well as the etiology of certain blinding diseases which include selective death of the visual cells.